Antenna aperture tuning

ABSTRACT

An antenna system includes: a radiating element; a feed coupled to the radiating element at a first point on the radiating element and configured to convey energy to the radiating element; and a radiation-adjustment device coupled to the radiating element at a second point, configured to alter a radiation characteristic of the radiating element, and including: coarse-adjustment elements; an integrated-circuit chip including: switches, each coupled to a respective one of the coarse-adjustment elements where the coarse-adjustment elements are disposed external to the integrated-circuit chip; and a fine-adjustment circuit; the antenna system further including a controller communicatively coupled to the switches and to the fine-adjustment circuit, the controller configured to alter the radiation characteristic of the radiating element by selectively causing one or more of the switches to couple one or more of the coarse-adjustment elements to the radiating element, and by adjusting a value of the fine-adjustment circuit.

BACKGROUND

Wireless communication devices are increasingly popular and increasinglycomplex. For example, mobile telecommunication devices have progressedfrom simple phones, to smart phones with multiple communicationcapabilities (e.g., multiple cellular communication protocols, Wi-Fi,BLUETOOTH® and other short-range communication protocols),supercomputing processors, cameras, etc. Wireless communication deviceshave antennas to support communication over a range of frequencies. Anantenna by itself may not have adequate performance (e.g., sufficientlylow loss) over an entire desired frequency range for desiredcommunication functionality (e.g., transmit and receive). Further, asfeature sets of devices increase, more space is taken up by hardwareused to support the features, often reducing the space available foreach antenna, which may reduce the antenna efficiency or otherwiseaffect performance. To help maintain adequate performance, an aperturetuner may be used.

SUMMARY

An example of an antenna system includes: a radiating element; a feedcoupled to the radiating element at a first point on the radiatingelement and configured to convey energy to the radiating element; and aradiation-adjustment device coupled to the radiating element at a secondpoint on the radiating element different from the first point, theradiation-adjustment device being configured to alter a radiationcharacteristic of the radiating element and including: a plurality ofcoarse-adjustment elements; an integrated-circuit chip including: aplurality of switches each coupled to a respective one of the pluralityof coarse-adjustment elements wherein the plurality of coarse-adjustmentelements are disposed external to the integrated-circuit chip; and afine-adjustment circuit; the antenna system further including acontroller communicatively coupled to the plurality of switches and tothe fine-adjustment circuit, the controller being configured to alterthe radiation characteristic of the radiating element by selectivelycausing one or more of the plurality of switches to couple one or moreof the plurality of coarse-adjustment elements to the radiating element,and by adjusting a value of the fine-adjustment circuit.

Implementations of such an antenna system may include one or more of thefollowing features. The plurality of coarse-adjustment elements includeone or more inductors, or one or more capacitors, or a combinationthereof. The fine-adjustment circuit includes a variable capacitor. Thecontroller is configured to adjust the value of the fine-adjustmentcircuit dynamically in response to changing resonant frequency of theradiating element. The fine-adjustment circuit is coupled to a localground on the integrated-circuit chip. The plurality ofcoarse-adjustment elements and a fine-adjustment element of thefine-adjustment circuit are complementary metal-oxide semiconductordevices. The radiation characteristic is radiation efficiency. Thefine-adjustment circuit is coupled to the radiating element. Thefine-adjustment circuit is coupled to at least one of the plurality ofswitches. The plurality of switches is a plurality of first switches, afirst port of each of the plurality of first switches is coupled to theradiating element, a second port of each of the plurality of firstswitches is coupled to a respective one of the plurality ofcoarse-adjustment elements, and the radiation-adjustment device furtherincludes a plurality of second switches each coupled between the secondport of a respective one of the plurality of first switches and a localground on the integrated-circuit chip. The integrated-circuit chipincludes the controller.

An example of a wireless communication device includes: a housing; adisplay retained by the housing; a printed circuit board communicativelycoupled to the display and disposed in the housing; and an antennacommunicatively coupled to the printed circuit board, disposed in thehousing, and including: a radiating element including a strip of metaldisposed proximate to a wall of the housing; a feed coupled to theradiating element at a first location, the feed configured to providesignals to the radiating element; and an aperture tuner coupled to theradiating element at a second location, displaced from the firstlocation, the aperture tuner including an integrated-circuit chip and aband-selecting tuning element disposed external to theintegrated-circuit chip, the integrated circuit chip configured toselectively couple to the band-selecting tuning element such that theradiating element will radiate with at least a threshold level ofefficiency over a first frequency band while coupled to theband-selecting tuning element and over a second frequency band, separatefrom the first frequency band, while isolated from the band-selectingtuning element, the integrated-circuit chip including a fine-tuningelement configured to adjust a resonant frequency of the radiatingelement within the first frequency band and the second frequency band.

Implementations of such a device may include one or more of thefollowing features. The band-selecting tuning element includes aninductor. The fine-tuning element includes a variable capacitor. Thefine-tuning element is coupled to the radiating element. The fine-tuningelement is selectively coupled to the band-selecting tuning element. Theaperture tuner includes a first band-selecting tuning element, theaperture tuner further including a second band-selecting tuning element,the integrated circuit chip configured to selectively couple to thesecond band-selecting tuning element such that the radiating elementwill radiate with at least the threshold level of efficiency over athird frequency band, separate from the first frequency band and thesecond frequency band, while coupled to the second band-selecting tuningelement. The aperture tuner includes a plurality of band-selectingtuning elements each selectively coupled to the integrated-circuit chipsuch that the aperture tuner is configured to cause the radiatingelement to radiate with at least the threshold level of efficiency overa selected one of a plurality of frequency bands including the firstfrequency band and the second frequency band. A lowest frequency in theplurality of frequency bands is separated by at least 600 MHz from ahighest frequency in the plurality of frequency bands.

Also or alternatively, implementations of such a device may include oneor more of the following features. The plurality of band-selectingtuning elements includes two or more inductors, or two or morecapacitors, or a combination of one or more inductors and one or morecapacitors. The device may further include a controller configured tocause a value of the fine-tuning element to change in response to achange in the resonant frequency of the radiating element. Thecontroller is configured to cause the value of the fine-tuning elementto change to counteract the change in the resonant frequency of theradiating element.

An example of an antenna includes: radiating means for radiatingelectromagnetic energy; signal means for providing a signal to theradiating means; means for tuning the radiating means to have areflection coefficient below a threshold value over a desired frequencyband; and an integrated circuit coupled to the means for tuning, themeans for tuning being external to the integrated circuit, theintegrated circuit including: means for selecting the means for tuning;and means for adjusting the means for tuning to adjust the desiredfrequency band.

Implementations of such an antenna may include one or more of thefollowing features. The means for tuning are for tuning the radiatingmeans to have the reflection coefficient below the threshold value overa selected one of a first plurality of desired frequency bands havingcenter frequencies separated by first increments, and the means foradjusting are for adjusting the means for tuning to adjust the desiredfrequency band to an adjusted frequency band between adjacent ones ofthe first plurality of desired frequency bands. The means for adjustingare for adjusting the means for tuning to adjust the desired frequencyband to a selected one of a second plurality of desired frequency bandshaving center frequencies separated by second increments that aresmaller than the first increments.

An example of an antenna aperture tuner includes: an output pinconfigured to be coupled to a radiating element; a plurality ofcoarse-adjustment pins; a plurality of switches each coupled to theoutput pin and to a corresponding one of the plurality ofcoarse-adjustment pins; and a fine-adjustment circuit coupled to theoutput pin; where the plurality of switches are configured to couple oneor more of the plurality of coarse-adjustment pins to the output pin andwhere the fine-adjustment circuit is configured to provide a selectablereactance to the output pin.

Implementations of such an antenna aperture tuner may include one ormore of the following features. The antenna aperture tuner may furtherinclude a controller communicatively coupled to the plurality ofswitches and to the fine-adjustment circuit and configured to actuatethe plurality of switches to couple one or more of the plurality ofcoarse-adjustment pins to the output pin and to control thefine-adjustment circuit to provide a selected reactance to the outputpin. The controller is configured to control the fine-adjustment circuitdynamically in response to changing resonant frequency of the radiatingelement. The antenna aperture tuner may further include a Unique SlaveIdentifier port, a Voltage Input/Output port, a data port, a clock port,and a ground port, where the controller is coupled to the Unique SlaveIdentifier port, the Voltage Input/Output port, the data port, the clockport, and the ground port. The fine-adjustment circuit includes avariable capacitor in parallel with a discharge short.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a communication system.

FIG. 2 is a block diagram of components of a wireless communicationdevice shown in FIG. 1.

FIG. 3 is a block diagram of components of a controller shown in FIG. 2.

FIG. 4 is a block diagram of components of an example of an aperturetuner shown in FIG. 2.

FIG. 5 is a diagram of plots of reflection coefficient for differentconfigurations of adjustment elements shown in FIG. 4.

FIG. 6 is a block flow diagram of a method of aperture tuning aradiating element of an antenna.

FIG. 7 is a block diagram of components of another example of theaperture tuner shown in FIG. 2.

FIG. 8 is a block diagram of output pins of the aperture tuner shown inFIG. 7.

DETAILED DESCRIPTION

Techniques are discussed herein for tuning an aperture of a radiatingelement of an antenna. For example, an aperture tuner is connected tothe radiating element at a location displaced from where a feed connectsto the radiating element for supplying a signal to be radiated or forreceiving incoming signals. The aperture tuner includes multiplecoarse-adjustment elements and an integrated-circuit chip. The chip hasmultiple switches connected to the coarse-adjustment elements, and afine-adjustment element. A controller can cause the switches to connect,or not, one or more of the coarse-adjustment elements to the radiatingelement and can set a value of the fine-adjustment element in order totune the radiating element as desired. The radiating element can betuned dynamically in accordance with a changing resonant frequency ofthe radiating element. The coarse-adjustment elements may, for example,be inductors and the fine-adjustment element may, for example, be avariable capacitor. Further, the fine-adjustment element may beselectively (either permanently or temporarily) connected to one or moreoutputs corresponding to one or more coarse-adjustment elements, e.g.,in parallel, and the combination(s) of the fine-adjustment element andthe coarse-adjustment element(s) selectively coupled to the radiatingelement. These examples are not exhaustive, and other configurations maybe used.

Items and/or techniques described herein may provide one or more of thefollowing capabilities, as well as other capabilities not mentioned. Anantenna can be tuned to operate over a wide tuning range, e.g., 600 MHz,with good efficiency. An antenna can be tuned to adapt to one or morechanges in environmental conditions to radiate efficiently at a desiredfrequency. Both coarse and fine-tuning of an antenna aperture can beprovided. Other capabilities may be provided and not everyimplementation according to the disclosure must provide any, let aloneall, of the capabilities discussed. Further, it may be possible for aneffect noted above to be achieved by means other than that noted, and anoted item/technique may not necessarily yield the noted effect.

Referring to FIG. 1, a communication system 10 includes wirelesscommunication devices 12, a network 14, a server 16, and access points(APs) 18, 20. The system 10 is a communication system in that componentsof the system 10 can communicate with one another directly orindirectly, e.g., via the network 14 and/or one or more of the accesspoints 18, 20 (and/or one or more other devices not shown, such as oneor more base transceiver stations). For indirect communications, thecommunications may be altered during transmission from one entity toanother, e.g., to alter header information of data packets, to changeformat, etc. The example wireless communication devices 12 shown includemobile phones (including smartphones), a laptop computer, and a tabletcomputer. Still other mobile devices may be used, whether currentlyexisting or developed in the future.

Referring also to FIG. 2, an example of any of the wirelesscommunication devices 12 includes an antenna 30, that includes aradiating element 32 and an aperture tuner 34, front-end circuitry 36,and a controller 38. The front-end circuitry 36 is communicativelycoupled to the controller 38 by one or more transmission lines, and isconnected to the radiating element 32 by a feed 40. In some embodiments,the front-end circuitry 36 may include an impedance matching circuit 37.For example, the feed 40 may be coupled to the impedance matchingcircuit 37 of the front-end circuitry 36. The impedance matching circuit37 is configured to attempt to match the output impedance of thefront-end circuitry 36 to the input impedance of the radiating element32 to reduce loss by reducing reflection of signals from the front-endcircuitry 36 by the radiating element 32. The front-end circuitry 36 andthe aperture tuner 34 are coupled to the radiating element 32 atdifferent, spaced apart locations. The locations of the connections tothe radiating element 32 may be selected based on the physicalconfiguration of the radiating element 32 and the effects on tunabilityand losses of the locations of the connections, and based on the voltagerequirements of the radiating element 32. The controller 38 and thefront-end circuitry 36 may provide multiple signal chains that may beused, for example, to communicate in different networks and/or fordifferent purposes (e.g., Wi-Fi communication, multiple frequencies ofWi-Fi communication, satellite positioning, one or more types ofcellular communications (e.g., GSM (Global System for Mobiles), CDMA(Code Division Multiple Access), LTE (Long-Term Evolution), 5G, etc.).The controller 38 may be configured to send communication signals to,and to receive communication signals from, the front-end circuitry 36.The controller 38 may be configured to produce an outbound communicationsignal, for example in a baseband, and to send this signal to atransmitter of the front-end circuitry 36. The communication signalprovides appropriate information, e.g., outgoing voice, uploading data,etc. for transmission by the front-end circuitry 36, e.g., to a cellulartower, an access point, etc., via the radiating element 32. Thecontroller 38 may be further configured to receive an inboundcommunication signal from a receiver of the front-end circuitry 36received via the radiating element 32. The sensor(s) 42 comprise one ormore sensors configured to measure one or more environmental conditionsand provide one or more corresponding indications to the controller 38.For example, the sensor(s) 42 include a temperature sensor configured tomeasure and provide an indication of the temperature of the wirelesscommunication device 12, e.g., of a printed circuit board (PCB), of thewireless communication device 12, that comprises the front-end circuitry36, the controller 38, and the sensor(s) 42.

The controller 38 may be configured to provide control signals to theaperture tuner 34 to control tuning of the radiating element 32 by theaperture tuner 34. For example, the controller 38 may be configured torespond to selection of a communication protocol, e.g., by selection ofa cellular service provider (e.g., according to a subscriberidentification module in the wireless communication device 12), bysending control signals to the aperture tuner 34 to tune the radiatingelement 32 for good efficiency at the frequency corresponding to theselected cellular service provider. The control signals may directlycause the aperture tuner 34 to tune the radiating element 32, e.g., bydirectly causing one or more switches to be open or closed and/or to seta value of a variable element, or may indirectly cause the aperturetuner 34 to tune the radiating element, e.g., by being interpreted andconverted to further control signals within the aperture tuner 34 asdiscussed below. The control signals (or further control signals) mayselectively actuate one or more switches of the aperture tuner 34 totune the radiating element 32. The controller 38 may produce and sendsignals to DATA and CLK ports (discussed further below) of the tuner 34in order to cause the tuner 34 to set switches to provide desired tuning(e.g., impedance). The controller 38 may be configured to produce thesignals for the DATA and/or CLK ports based on a desired frequency bandof operation of the radiating element 32 that the tuner 34 converts intocontrol signals for selectively opening and closing appropriate ones ofthe switches.

Referring also to FIG. 3, the controller 38 comprises a computer systemincluding a processor 50 and memory 52, including software 54. Theprocessor 50 may be an intelligent hardware device, e.g., a centralprocessing unit (CPU) such as those made by QUALCOMM®, ARM®, Intel®Corporation, or AMD®, a microcontroller, an application specificintegrated circuit (ASIC), etc. The processor 50 could comprise multipleseparate physical entities that can be distributed in the wirelesscommunication device 12. The memory 52 is a non-transitory storagemedium that includes random access memory (RAM) and read-only memory(ROM). The memory 52 stores the software 54 which is processor-readable,processor-executable software code containing instructions that areconfigured to, when executed, cause the processor 50 to perform variousfunctions described herein (although the description may refer only tothe processor 50, or the controller 38, performing the functions).Alternatively, the software 54 may not be directly executable by theprocessor 50 but configured to cause the processor 50, e.g., whencompiled and executed, to perform the functions. The controller 38 isdisposed externally to an integrated circuit chip of the aperture tuner34 (i.e., a tuner chip), and may be part of a modem processor and/orpart of an applications processor, etc.

Referring to FIG. 4, with further reference to FIG. 2, an example of theaperture tuner 34 comprises an integrated-circuit (IC) chip 60 andcoarse-adjustment elements 62, 63, 64, 65. The IC chip 60 includes pins66, 67, 68, 69 coupled (directly or indirectly) to the coarse-adjustmentelements 62, 63, 64, 65, respectively, and a pin 70 connected to theradiating element 32. The IC chip 60 includes switches 72, 73, 74, 75,76, 77, 78, 79, a fine-adjustment element 80, an electrostatic-dischargeshort 82, and a digital/analog controller 84. The coarse-adjustmentelements 62-65 are configured to affect a radiation frequency of theradiating element 32 in large increments (e.g., in steps of about 70 MHzas shown in FIG. 5) while the fine-adjustment element 80 may beconfigured to vary the radiation frequency of the radiating element 32in smaller increments over a range of about one large increment of thecoarse-adjustment elements 62-65. The size of the coarse increments maybe, for example, three, four, or five, etc. times the size of the smallincrements of the fine-adjustment element 80 and may depend on agranularity of increments/variation of the fine-adjustment element 80.Here, the coarse-adjustment elements 62, 64 are inductors and thecoarse-adjustment elements 63, 65 may be inductors, capacitors, or acombination thereof. Thus, each of the coarse-adjustment elements 62-65comprises one or more reactances. The coarse-adjustment elements 62, 64may not be inductors in other implementations, instead being capacitors,a combination of an inductor and a capacitor, or other configuration.Further, as used herein, an inductor may comprise multiple physicalcomponents and a capacitor may comprise multiple physical components. Inthe example shown in FIG. 4, the fine-adjustment element 80 is avariable reactance, here a variable capacitor, but other configurationsof the fine-adjustment element 80 may be used. The aperture tuner 34 isconfigured to selectively alter a radiation characteristic, e.g., aradiation efficiency and/or an antenna pattern, of the radiating element32. One or more of the coarse-adjustment elements 62-65 and/or thefine-adjustment element 80 made be a complementary metal-oxidesemiconductor device. The fine-adjustment element 80 and the dischargeshort 82 are coupled in parallel and form a fine-adjustment circuit 83.The discharge short 82 is configured to close in response to anelectrical surge, e.g., due to electrostatic discharge, to bypass thefine-adjustment element, shorting the connection to the radiatingelement 32 to local ground. Alternatively, a fine-adjustment circuitcould have the fine-adjustment element 80 coupled in series with aswitch that is coupled to the pin 70 and the switch selectively openedto inhibit the fine-adjustment element 80 affecting the radiatingelement 32 or closed to facilitate the fine-adjustment element 80affecting the radiating element 32. Alternatively still, afine-adjustment circuit may not include a switch or the discharge short82, e.g., including only the fine-adjustment element 80.

The switches 72-79 are controlled by the controller 84 to open or closeto affect the radiation characteristic of the radiating element 32 asdesired. The controller 84 is configured to selectively actuate theswitches 72-79 to be open or closed to help provide a desired radiationcharacteristic of the radiating element 32. Here, the controller 84 isshown as being on the IC chip 60, but other configurations may be usedwhere the controller 84 is disposed (all or partially) off the IC chip60. In the illustrated embodiment, the controller 84 has a USID (UniqueSlave ID (Identifier)) port, a VIO (Voltage Input/Output) port, a data(DATA) port, a clock (CLK) port, and a ground (GND) port, but in otherembodiments the controller may omit one or more of these ports (forexample the USID port). The USID provides a selector for configurationswith multiple aperture tuners on a single data bus. Supply voltage forthe IC chip 60 (e.g., for the switches 72-79, the capacitor 80, and thecontroller 84) may be provided via the VIO port. The controller 84 mayreceive, from the controller 38, signals on the DATA port (that may bebi-directional) and the CLK port that instructs the controller 84 as towhich of the switches 72-79 to open and which of the switches 72-79 toclose. The controller 84 decodes the values of the signals on the DATAand/or CLK ports into corresponding signals to set each of the switches72-79 to be open or closed, respectively. The controller 84 may beconfigured to operate within an RF Front-End Control Interface (RFFE℠)defined by the MIPI (Mobile Industry Processor Interface) Alliance. Asshown, when a switch (here, the switches 72, 73) selectively coupling acoarse-adjustment element (here, the coarse-adjustment elements 62, 63)to the radiating element 32 is open, then the switch (here, the switches76, 77) selectively coupling that coarse-adjustment element to thelocal, on-chip ground 86 is closed. Conversely, when a switch (here, theswitches 74, 75) selectively coupling a coarse-adjustment element (here,the coarse-adjustment elements 64, 65) to the radiating element 32 isclosed, then the switch (here, the switches 78, 79) selectively couplingthat coarse-adjustment element to the local, on-chip ground 86 is open.The aperture tuner 34 may be configured to couple only onecoarse-adjustment element (or none) at a time to the radiating element32 or may be configured to couple combinations of the coarse-adjustmentelements to the radiating element 32. Those of skill in the art willunderstand that a greater or smaller number of ports may be implementedin the IC chip 60. For example, the USID port may be omitted in someimplementations. In some embodiments, several data ports may beimplemented, and in some such embodiments the controller 84 may beconfigured to determine how to appropriately configure the switches72-79 when instructions from multiple sources are received.

The aperture tuner 34 may change the radiation characteristic of theradiating element 32 by selectively coupling one or more of thecoarse-adjustment elements 62-65 to the radiating element 32 and/oradjusting a value of the fine-adjustment element 80, e.g., acapacitance. The switches 72-75 may be selectively closed, therebyelectrically coupling the respective coarse-adjustment elements 62-65 tothe radiating element 32, or opened, thereby electrically isolating therespective coarse-adjustment elements 62-65 from the radiating element32. The switches 76-79 may be selectively closed, thereby electricallycoupling the respective coarse-adjustment elements 62-65 to a local,on-chip ground 86, or opened, thereby electrically isolating therespective coarse-adjustment elements 62-65 from the ground 86. Thecontroller 84 is further configured to provide a control signal to thefine-adjustment element 80 to adjust a value of the fine-adjustmentelement 80. In some embodiments, the fine-adjustment element 80 isimplemented using a plurality of switched capacitors in parallel, andthe controller 84 transmits control signals to respective switches ofthe fine-adjustment element 80 to control whether each of those switchesis open or closed. In the closed configuration, the respective capacitoris coupled through the switch to the local ground. As discussed above,control signals may be produced in response to one or more signalsreceived by the controller 84, e.g., on the DATA port and/or the CLKport, from the controller 38. Also or alternatively, the controller 84may be configured to produce one or more control signals to adjust thevalue of the fine-adjustment element 80 dynamically in response tochanging resonant frequency of the radiating element 32, e.g., due to achange in one or more environmental conditions such as temperature ofthe antenna 30 as indicated by the sensor(s) 42. The controller 84 mayadjust the value of the fine-adjustment element 80 to counteract thechanges in the resonant frequency due to the one or more environmentalconditions to try to maintain the resonant frequency of the radiatingelement 32, or at least not have the resonant frequency change so muchthat the radiating element cannot sufficiently efficiently transmit orreceive signals at a desired frequency.

Referring also to FIG. 5, selectively opening and closing the switches72-75 cause large adjustments to the radiation characteristic, here theradiation efficiency, of the radiating element 32. FIG. 5 shows exampleplots 111, 112, 113, 114, 115 of reflection coefficient (S₁₁) vs.frequency for different coarse-adjustment elements being coupled to theradiating element 32. The coarse-adjustment elements 62-65 in theexample of FIG. 5 are all inductors with large inductance values, e.g.,1-60 nH, and can make large changes to a frequency band over which theradiating element 32 radiates efficiently, e.g., radiates more than athreshold amount of input energy and correspondingly reflects less thana threshold 110 amount of the input energy. In FIG. 5, plots 111-115correspond to the switches 72-75 all being open, only the switch 72being closed, only the switch 73 being closed, only the switch 74 beingclosed, and only the switch 75 being closed, respectively. The plots111-115 show the reflection coefficient at the feed 40 (FIG. 2) for thecorresponding configurations of the switches 72-75. As shown, withlarger inductance values connected to the radiating element 32 (i.e.,going from the plot 111 to the plot 115), the frequencies are higher atwhich the reflection coefficient is below the threshold 110. That is,the frequency band over which the radiation efficiency is desirable (theefficient radiation frequency band) is higher (i.e., spans higherfrequencies) as the inductance coupled to the radiating element 32increases. The efficient radiation frequency bands corresponding to thecoarse-adjustment elements 62-65 correspond to the values of thecoarse-adjustment elements 62-65 and the separations of the efficientradiation frequency bands correspond (although not necessarily linearly)to the differences in the values of the coarse-adjustment elements62-65.

As also shown in FIG. 5, changing the value of the fine-adjustmentelement 80 causes small changes to the radiation characteristic of theradiating element 32. In this example, as the capacitance of thefine-adjustment element 80 is increased, the efficient radiationfrequency band decreases, e.g., a plot corresponding to the switch 73being closed changes from the plot 113 to a plot 116, with the plot 116shifted lower in frequency relative to the plot 113. Also, the plot 116has an efficient radiation frequency band that is slightly larger thanfor the plot 113, and has a minimum reflection coefficient 117 that islower than a minimum reflection coefficient 118 for the plot 113. Therange of fine-tune adjustment may be larger than as shown with the plots113, 116, and ranges of fine-tune adjustment are available for eachconfiguration of coupling of the coarse-adjustment elements 62-65 to theradiating element 32.

The quantities and scale illustrated in FIG. 5 are examples only, andembodiments are not limited to those illustrated in FIG. 56. The valuesof the coarse-adjustment elements 62-65 and the range of values of thefine-adjustment element 80 may be selected such that the efficientradiation frequency bands span frequency ranges of interest. Forexample, values may be selected such that the efficient radiationfrequency bands span frequency ranges (i.e., from a lowest frequency inthe range to a highest frequency in the range) used for receiving andtransmitting signals for one or more communication protocols such as 4GLTE, 5G LTE, etc. Thus, while frequencies under 1 GHz are illustrated inFIG. 5, the aperture tuner 34 may be configured for use in systems thattransmit and/or receive at frequencies below 2 GHz, below 3.5 GHz, etc.The efficient radiation frequency bands may extend over a large range offrequencies, e.g., with a lowest frequency in one of efficient radiationfrequency bands differing from a highest frequency in another of theefficient radiation frequency bands by 600 MHz or more (this differencebeing about 300 MHz as shown in FIG. 5).

Referring to FIG. 6, with further reference to FIGS. 1-5, a method 150of aperture tuning a radiating element of an antenna includes the stagesshown. The method 150 is, however, an example only and not limiting.

At stage 152, the method 150 includes coupling one or more of aplurality of coarse-adjustment elements to a radiating element of theantenna to set a radiation characteristic of the radiating element, thecoarse-adjustment elements being disposed externally to anintegrated-circuit chip of the antenna. For example, the controller 84can respond to information on the DATA port and/or the CLK port bydetermining a configuration of the coarse-adjustment elements 62-65, ifany, to couple to the radiating element 32. Coupling one or more of thecoarse-adjustment elements to the radiating element comprises couplingone or more inductors, or one or more capacitors, or a combinationthereof, to the radiating element.

At stage 154, the method 150 includes setting a value of a component ofthe integrated-circuit chip to affect the radiation characteristic. Forexample, the controller 84 may send a control signal to set (which maychange) the capacitance value of the fine-adjustment element 80. Thecontroller 84 may produce the control signal in response to informationfrom the controller 38, e.g., information regarding one or more measuredenvironmental conditions measured by the sensor(s) 42. The radiationcharacteristic may be an efficient radiation frequency band and settingthe value of the component of the integrated-circuit chip may set arange of the efficient radiation frequency band. As another example ofstage 154, setting the value of the component of the integrated-circuitchip may comprise adjusting the value of the component dynamically inresponse to changing resonant frequency of the radiating element. Forexample, the controller 84 may set the capacitance value of thefine-adjustment element 80 in response to indications from thecontroller 38, e.g., indicating a value of the fine-adjustment element80 to be used or indicating one or more measured environmentalconditions.

Configurations other than those discussed above may be used. Forexample, referring to FIG. 7, with further reference to FIG. 2, anaperture tuner 170 (which may be another example of the aperture tuner34 shown in FIG. 2) may be configured similarly to the aperture tuner 34shown in FIG. 4, with the aperture tuner 170 including an IC chip 160that is slightly different than the IC chip 60 shown in FIG. 4. The ICchip 160 has a fine-adjustment element 162 and anelectrostatic-discharge short 164 that are similar to thefine-adjustment element 80 and the electrostatic-discharge short 82shown in FIG. 4, but instead of being coupled to the pin 70 as shown inFIG. 4, the element 162 and the discharge short 164 are coupled to a pin166 that is configured to be coupled to one of the pins 66, 67, 68, 69,or 70. For example, the pin 166 may be wired to one of the pins 66, 67,68, 69, or 70 during manufacture. Which of the pins 66-70 the pin 166 iscoupled to may depend on a purpose of the radiating element 32. Forexample, the pin 166 may be selectively coupled to one of the pins 66-70depending on whether the radiating element 32 is a cellular antenna(and/or depending on a band of the cellular antenna), a Wi-Fi antenna, aBluetooth® antenna, etc. The pin 166 may be selectively coupled to oneor more of the pins 66-70, e.g., through a switch 172 (that is optional,as indicated by the dashed line in FIG. 7) controlled by a controller168 of the IC chip 160 (although in other configurations the controller168 may be disposed off the IC chip 160). Alternatively, the pin 166 maybe permanently coupled (e.g., hard-wired by a PCB trace or wire jumper)to one or more of the pins 66-70, e.g., during manufacture of theaperture tuner 170. As another example, referring also to FIG. 8, abottom 174 of the IC chip 160 may provide the pins 66-70, 166, and USID,VIO, DATA, GND, and CLK pins for the corresponding ports. The pin 166may be hard-wire connected to one of the pins 66-70 by physicallyconnecting a wire from the pin 166 to a desired one of the pins 66-70.

By using the configuration of FIG. 7, the fine-adjustment element 162may be selectively coupled to the radiating element 32. Thefine-adjustment element 162 may be connected in parallel with one of theexternal elements, and the parallel combination selectively connected(e.g., “permanently” (e.g., by a wire) or “temporarily” (e.g., via aswitch)) to the radiating element 32. Further, with the respective oneof the switches 72-75 open, the fine-adjustment element 162 may beisolated from the radiating element 32.

Other Considerations

Also, as used herein, “or” as used in a list of items prefaced by “atleast one of” or prefaced by “one or more of” indicates a disjunctivelist such that, for example, a list of “at least one of A, B, or C,” ora list of “one or more of A, B, or C” means A or B or C or AB or AC orBC or ABC (i.e., A and B and C), or combinations with more than onefeature (e.g., AA, AAB, ABBC, etc.).

As used herein, unless otherwise stated, a statement that a function oroperation is “based on” an item or condition means that the function oroperation is based on the stated item or condition and may be based onone or more items and/or conditions in addition to the stated item orcondition.

Further, an indication that information is sent or transmitted, or astatement of sending or transmitting information, “to” an entity doesnot require completion of the communication. Such indications orstatements include situations where the information is conveyed from asending entity but does not reach an intended recipient of theinformation. The intended recipient, even if not actually receiving theinformation, may still be referred to as a receiving entity, e.g., areceiving execution environment. Further, an entity that is configuredto send or transmit information “to” an intended recipient is notrequired to be configured to complete the delivery of the information tothe intended recipient. For example, the entity may provide theinformation, with an indication of the intended recipient, to anotherentity that is capable of forwarding the information along with anindication of the intended recipient.

Substantial variations may be made in accordance with specificrequirements. For example, customized hardware might also be used,and/or particular elements might be implemented in hardware, software(including portable software, such as applets, etc.) executed by aprocessor, or both. Further, connection to other computing devices suchas network input/output devices may be employed.

The methods, systems, and devices discussed above are examples. Variousconfigurations may omit, substitute, or add various procedures orcomponents as appropriate. For instance, in alternative configurations,the methods may be performed in an order different from that described,and that various steps may be added, omitted, or combined. Also,features described with respect to certain configurations may becombined in various other configurations. Different aspects and elementsof the configurations may be combined in a similar manner. Also,technology evolves and, thus, many of the elements are examples and donot limit the scope of the disclosure or claims.

Specific details are given in the description to provide a thoroughunderstanding of example configurations (including implementations).However, configurations may be practiced without these specific details.For example, well-known circuits, processes, algorithms, structures, andtechniques have been shown without unnecessary detail in order to avoidobscuring the configurations. This description provides exampleconfigurations only, and does not limit the scope, applicability, orconfigurations of the claims. Rather, the preceding description of theconfigurations provides a description for implementing describedtechniques. Various changes may be made in the function and arrangementof elements without departing from the spirit or scope of thedisclosure.

Also, configurations may be described as a process which is depicted asa flow diagram or block diagram. Although each may describe theoperations as a sequential process, many of the operations can beperformed in parallel or concurrently. In addition, the order of theoperations may be rearranged. A process may have additional stages orfunctions not included in the figure. Furthermore, examples of themethods may be implemented by hardware, software, firmware, middleware,microcode, hardware description languages, or any combination thereof.When implemented in software, firmware, middleware, or microcode, theprogram code or code segments to perform the tasks may be stored in anon-transitory computer-readable medium such as a storage medium.Processors may perform the described tasks.

Components, functional or otherwise, shown in the figures and/ordiscussed herein as being coupled, connected, or communicating with eachother are communicatively coupled. That is, they may be directly orindirectly connected, possibly wirelessly connected, to enablecommunication between them. Further, components described as beingcoupled are directly or indirectly (e.g., via another component such asa switch, a resistor, etc.) electrically connected, e.g., via a wire orother conductive connector.

Having described several example configurations, various modifications,alternative constructions, and equivalents may be used without departingfrom the spirit of the disclosure. For example, the above elements maybe components of a larger system, wherein other rules may takeprecedence over or otherwise modify the application of the invention.Also, a number of operations may be undertaken before, during, or afterthe above elements are considered. Accordingly, the above descriptiondoes not bound the scope of the claims.

Further, more than one invention may be disclosed.

1. An antenna system comprising: a radiating element; a feed coupled tothe radiating element at a first point on the radiating element andconfigured to convey energy to the radiating element; and aradiation-adjustment device coupled to the radiating element at a secondpoint on the radiating element different from the first point, theradiation-adjustment device being configured to alter a radiationcharacteristic of the radiating element and comprising: a plurality ofcoarse-adjustment elements; an integrated-circuit chip comprising: aplurality of switches each coupled to a respective one of the pluralityof coarse-adjustment elements and a pin, wherein the plurality ofcoarse-adjustment elements are disposed external to theintegrated-circuit chip, and wherein the pin is coupled to the radiatingelement at the second point; and a fine-adjustment circuit coupled tothe pin; and a controller communicatively coupled to the plurality ofswitches and to the fine-adjustment circuit, the controller beingconfigured to alter the radiation characteristic of the radiatingelement by selectively causing one or more of the plurality of switchesto couple one or more of the plurality of coarse-adjustment elements tothe radiating element via the pin, and by adjusting a value of thefine-adjustment circuit.
 2. The antenna system of claim 1, wherein theplurality of coarse-adjustment elements comprise one or more inductors,or one or more capacitors, or a combination thereof.
 3. The antennasystem of claim 1, wherein the fine-adjustment circuit comprises avariable capacitor.
 4. The antenna system of claim 1, wherein thecontroller is configured to adjust the value of the fine-adjustmentcircuit dynamically in response to changing resonant frequency of theradiating element.
 5. The antenna system of claim 1, wherein thefine-adjustment circuit is coupled to a local ground on theintegrated-circuit chip.
 6. The antenna system of claim 1, wherein theplurality of coarse-adjustment elements and a fine-adjustment element ofthe fine-adjustment circuit are complementary metal-oxide semiconductordevices.
 7. The antenna system of claim 1, wherein the radiationcharacteristic is radiation efficiency.
 8. The antenna system of claim1, wherein the fine-adjustment circuit is coupled to the radiatingelement.
 9. The antenna system of claim 1, wherein the fine-adjustmentcircuit is coupled to at least one of the plurality of switches.
 10. Theantenna system of claim 1, wherein the plurality of switches is aplurality of first switches, wherein a first port of each of theplurality of first switches is coupled to the radiating element, whereina second port of each of the plurality of first switches is coupled to arespective one of the plurality of coarse-adjustment elements, andwherein the radiation-adjustment device further comprises a plurality ofsecond switches each coupled between the second port of a respective oneof the plurality of first switches and a local ground on theintegrated-circuit chip.
 11. The antenna system of claim 1, wherein theintegrated-circuit chip includes the controller.
 12. A wirelesscommunication device comprising: a housing; a display retained by thehousing; a printed circuit board communicatively coupled to the displayand disposed in the housing; and an antenna communicatively coupled tothe printed circuit board, disposed in the housing, and comprising: aradiating element comprising a strip of metal disposed proximate to awall of the housing; a feed coupled to the radiating element at a firstlocation, the feed configured to provide signals to the radiatingelement; and an aperture tuner coupled to the radiating element at asecond location, displaced from the first location, the aperture tunercomprising an integrated-circuit chip and a band-selecting tuningelement disposed external to the integrated-circuit chip, the integratedcircuit chip configured to selectively couple to the band-selectingtuning element to the radiating element at the second location such thatthe radiating element will radiate with at least a threshold level ofefficiency over a first frequency band while coupled to theband-selecting tuning element and over a second frequency band, separatefrom the first frequency band, while isolated from the band-selectingtuning element, the integrated-circuit chip including a fine-tuningelement configured to be coupled to the second location and to adjust aresonant frequency of the radiating element within the first frequencyband and the second frequency band.
 13. The device of claim 12, whereinthe band-selecting tuning element comprises an inductor.
 14. The deviceof claim 12, wherein the fine-tuning element comprises a variablecapacitor.
 15. The device of claim 12, wherein the fine-tuning elementis coupled to the radiating element.
 16. The antenna of claim 12,wherein the fine-tuning element is selectively coupled to theband-selecting tuning element.
 17. The device of claim 12, wherein theaperture tuner comprises a first band-selecting tuning element, theaperture tuner further comprising a second band-selecting tuningelement, the integrated circuit chip configured to selectively couple tothe second band-selecting tuning element such that the radiating elementwill radiate with at least the threshold level of efficiency over athird frequency band, separate from the first frequency band and thesecond frequency band, while coupled to the second band-selecting tuningelement.
 18. The device of claim 12, wherein the aperture tunercomprises a plurality of band-selecting tuning elements each selectivelycoupled to the integrated-circuit chip such that the aperture tuner isconfigured to cause the radiating element to radiate with at least thethreshold level of efficiency over a selected one of a plurality offrequency bands including the first frequency band and the secondfrequency band.
 19. The device of claim 18, wherein a lowest frequencyin the plurality of frequency bands is separated by at least 600 MHzfrom a highest frequency in the plurality of frequency bands.
 20. Thedevice of claim 18, wherein the plurality of band-selecting tuningelements comprises two or more inductors, or two or more capacitors, ora combination of one or more inductors and one or more capacitors. 21.The device of claim 12, further comprising a controller configured tocause a value of the fine-tuning element to change in response to achange in the resonant frequency of the radiating element.
 22. Thedevice of claim 21, wherein the controller is configured to cause thevalue of the fine-tuning element to change to counteract the change inthe resonant frequency of the radiating element.
 23. An antennacomprising: radiating means for radiating electromagnetic energy, theradiating means comprising a first location and a second location spacedapart; signal means for providing a signal to the radiating means at thefirst location; means for tuning the radiating means to have areflection coefficient below a threshold value over a desired frequencyband; and an integrated circuit coupled to the means for tuning, themeans for tuning being external to the integrated circuit, theintegrated circuit comprising: means for selecting the means for tuning;means for adjusting the means for tuning to adjust the desired frequencyband; and means for coupling the means for tuning and the means foradjusting to the second location.
 24. The antenna of claim 23, whereinthe means for tuning are for tuning the radiating means to have thereflection coefficient below the threshold value over a selected one ofa first plurality of desired frequency bands having center frequenciesseparated by first increments, and wherein the means for adjusting arefor adjusting the means for tuning to adjust the desired frequency bandto an adjusted frequency band between adjacent ones of the firstplurality of desired frequency bands.
 25. The antenna of claim 24,wherein the means for adjusting are for adjusting the means for tuningto adjust the desired frequency band to a selected one of a secondplurality of desired frequency bands having center frequencies separatedby second increments that are smaller than the first increments.
 26. Anantenna aperture tuner comprising: an output pin configured to becoupled to a radiating element; a plurality of coarse-adjustment pins; aplurality of switches each coupled to the output pin and to acorresponding one of the plurality of coarse-adjustment pins; afine-adjustment circuit coupled to the output pin; a controllercommunicatively coupled to the plurality of switches and to thefine-adjustment circuit; a Unique Slave Identifier port; a VoltageInput/Output port; a data port; a clock port; and a ground port, whereinthe plurality of switches are configured to couple one or more of theplurality of coarse-adjustment pins to the output pin, wherein thefine-adjustment circuit is configured to provide a selectable reactanceto the output pin, and wherein the controller is coupled to the UniqueSlave Identifier port, the Voltage Input/Output port, the data port, theclock port, and the ground port.
 27. The antenna aperture tuner of claim26, wherein the controller is configured to actuate the plurality ofswitches to couple one or more of the plurality of coarse-adjustmentpins to the output pin and to control the fine-adjustment circuit toprovide a selected reactance to the output pin.
 28. The antenna aperturetuner of claim 27, wherein the controller is configured to control thefine-adjustment circuit dynamically in response to changing resonantfrequency of the radiating element.
 29. (canceled)
 30. The antennaaperture tuner of claim 26, wherein the fine-adjustment circuitcomprises a variable capacitor in parallel with a discharge short.